Telephonogram apparatus.



No. 'lesew vwPATENTED AUG. z, 19o4.` o. HLSMBYER.

TBLEPHONOGRAMAPBARATUS.

Ammon-Ion rILnn 001213, 1902.

Bo Monat..

9.9i human Nofreese.

UNIIRD .STATES i Patented August 2, 1904.1

CHRISTIAN HLSMEYER, or DSSELDORF, GERMAIN.v

TEL'EPI-IoNoenwI APPARATUS.,

SPECFICATION forming'part of- Letters Patent No. 766,355, dated August 2, 1904:. Application nea october 13,1902. serial No. 127,117. (No model.:

7 To @illu/hom. itA may concern;

. Be it known thatI, CHRISTIAN 'HLsMnYEm engineer, a subject of the King of Prussia,

Emperor of Germany, residing at Bilker Allee 98, Dsseldorf, in the Kingdom of' Prussia,`

Germany, have invented certain new and useful Improvements in Te'lephonograr'n -Appa-g ratus, of which the followingis a full, clear,-

and exact description;

-This Ainvention relates to'apparatus'- for ith e- I Vconversion 'of -variations in lthe intensity ofelectric current into variations in the inten-v sity of light. y Y

In the devices hith'erto known for the conversion of variations of current intensity into va" riations in light intensity there have been used either polarized, dispers`ion,-o'1 1 V throttle de.-

" current variations of' the-electromagnets to be I absorbed or 'transmitted by Aa fixed plate the vices. These, however, fulfil thefrequirements made of them only imperfectly, 'because withr them not the quality but-the quantity of the' bundle of rays is controlled according to the variations of the current. For a perfect action of such devices it seemsnecessary that the control should proceed in direct or inverse proportion to the'current variations, which in thedevice formingtbe present inventlon 1s attained by causing the-bundle of rays falling upona mirror which oscillates in accordance with the transparency or power of absorption of which continuously increases or diminishes correspending to the sine of the. angle of incidence.

`I f'the arrangement is for vthe .purpose of.

throwing such rays through an aperture upon a given point. The arrangement is preferably so constructed that by altering the dis?l tancebetween the mirror and' thef'plateor' A prism system andthe light-aperture.thesemj sitiveness of the apparatus may be within the widestlimits` according tojtlife"re quirement without .alteration of the mechani f i the sensitivefband'r i's-more or lessdarkened.

ical parts.

The accompanying drawings show Lure 1 an arrangement of vthe kind se t forth diagrammatically lillustrated,while,'Flg. 1s

a detail view of the plate of varying transparency, and Fig. 3 is a detail view of the cylindrical lens.

Two stations are connected with one an-. othereither by a double-Wire connection' or a single Wire, with the earth asl return connection. f If the caller speaks into the telephone- 1 orf'microtelephone a, the constant current of 'the line-.battery b is subjected to yariations of `intensity, which result in varying the power` of attraction of the electromagnets al d', which fare inserted'in series in the line-current. Op-

posite' the electromagnets d d is placedan edual-armed lever e, which, controlled by the4 spring f, can oscillate easily to and fro. At

7both\ends the said lever carries two soft-iron' "plates gg and onits axis of revolution a lit-A tle mirror I. The entire apparatus of the receiving-station is placed in a dark chamber. 4Out of a light chambers' there is projected 'through a slit a bundle of'rays K upon the *mirror It, which rays are reflected. 'out again at the saine angle- The reliected ray p then penetrates a plate Z, Fig. v2, .the transparency. of .which constantly. decreases from m to n, Aand this in such a manner that the same is Aequal to unity at m and is equal to zero at n.

By'meansof a cylinder-lens o the bundle of rays is constantly retracted. towardv aline q,

Figs.- l and 3. #Altl the point q there is caused to Vpass uniformly-a sensitive s'tri'p'/| by means of a' clockworkloran electromotonwhich band is then d eanannerof thecinernatograph; Theoperationi-ofthe photochemical fixing @is asllfollowsa'lhevariations of resistance ingff'thre'ugh the soundwaves xin the'miphoner'causes'variations of intensity of hefl-ine-current, which are indicated'by the arying attractiompower of the electromag- .znetsfolfalll 'lfhe-lever ef i s \'con sequently more l or 'lessattract'eiand therefore the bundle of- '1f thenv the band 51,' -which has been exposed to ligbt and/fixed, lbe'fpassed in the 'well-known i manner'between a seleniumcell and asource 100 of light, the telephonegram will be. again heard in a telephone inserted in a constant# current circuit. is has been already stated, the distance between the mirror it and the platel or between the prism; system 0 and the light-aperture q should be adjustable. By this meansthe sensitiveness of the apparatus can be adjusted Within the widest limits according to the requirement without alteration of the mechanical parts. This may. be

' eiected in the most simple manner by arrang-l refiected by the mirror,

and desire to secure by Letmirror, means of unequal transparency, be

tween said mirror and said concentrating means for varying the intensity of the light, and a sensitive film for receiving the rays when concentrated.

.2. In a telephonogram apparatus, the combination of a telephone-circuit, a mirror,

-means operated by said circuit for oscillating the mirron; means for throwing a constant bundle of rays of light on said mirror, a lens system for concentrating to a band the rays. a transparent plate between the mirror and the lens system, the transparency of said plate increasing or diminishing continuously corresponding to the sine of the angle of incidence, and a sensitive iilm for receiving the rays when concentrated.

.3. In a teiephonogram apparatus the cornbination o a telephone-circuit, electromagnetic means in said circuit, an oscillating lever, a spring controlling said lever, armatures on said lever arranged opposite the electromagnetic means, a mirror on the axis of revolution of the lever, means for throwing a constant bundle of rays of light on the mirror, a lens system for collecting the rays relected by the mirror, a transparent plate between the mirror and the lens system, the

transparency of said plate increasing or di' minishing continuously corresponding to the sine of the angle of incidence, means for adjusting said transparent plate' and lens system, a sensitive film for receiving the rays when concentrated, and l,means forv rotating said film and leading it through a fixing-bath when exposed. 1

4. In a telephonogram apparatus, the cornbination of a' telephone-circuit, a mirror,

solenoids in said circuit for bscillating saidI mirror, a cylinder-lens for converging the reie-cted rays to a line, means of unequal transparency between said lens and said mirror,

anda sensitive film. l

In Witness whereof I subscribe my signature in presence of two witnesses.

CHRISTIAN HLSMEYER. VVitneSSes:

CARL SCHMITT, GUs'rAv SINNHOLD. 

